Electric incandescent lamp



(No Model.)

B. BERLINER. ELECTRIC INUANDESGENT LAMP.

No. 258,546. 7 Patented May 30,1882.

UNTTED STATES PATENT QFFICE.

ELECTRIC INCAN SPECIFICATION forming part of Letters DESCENT LAMP.

Patent No. 258,546, dated May 30, 1882.

Application filed March 31, 1882. (No model.)

To all whom it may concern:

Be it known that I, EMILE BERLINER, of Boston, in the county of Suffolk and State of Massachusetts, haveinventcd certain Improvelnentsin ElectriclncandescentLamps,ofwhich the following is a specification.

This invention refers to the class of electric lamps known as semi-incandescent; and it consists in the use of elastic carbon forming a loose electric contact, preferably by overlapping two such elastic carbons, and inclosing them in a vacuous chamber, of glass or other transparent or semi transparent material, which chamber is hermetically sealed afterward. I call elastic carbons all such as are produced by carbonizing vegetable fibers or their uncarbonized prod cots-as paper, pasteboard, 8m. Oarbons thus produced have a certain elasticity which distinguishes them from the ordinary mixed and baked carbons.

In the drawing, a d and c b are the two elastic carbons fixed to the platinum wires 1 and 2. The carbons are overlapping and in loose contact with one another at m. The two wires are sealed in the glass of the vacuous chamber A, and by connecting the outside wire ends with a sufficiently strong source of electricity an arc is produced at the loose contact a, and the parts of the carbons nearest the contact will become incandescent. The effect produced is that ofa so-called semi-incandescent light in cacao.

What I claim is-- 1. An electric lamp consisting of two electric carbons in loose contact with one another and inclosed in a transparent or semi-transparent vacuous chamber.

2. An electric lamp consisting of two conductors overlapping and in loose contact with one another and inclosed in a vacuum.

3. In an electric lamp, a vacuous chamber containing a conductor consisting of elastic carbon, as described, and in loose contact with another conductor, substantially as described.

In testimony whereof I have signed my name to this specificatiomin the presence of two subscribing witnesses, this 29th day of March,

EMILE BERLINER.

Witnesses GEO. WILLIs PIERCE, O. H. M. HAZEL. 

